Composition for cleaning lithographic stones.



AL NX Ace-Tic. A -4D A can UNITED STATES PATENT OFFICE.

Specification of Letters Patent,

Patented Feb. 27, 1906.

Application filed December 4, 1905. Serial No. 290,092.

To all whom, it may concern.-

Be it known that I, JOSEPH JAMES, a citizen of the United States,residing at Baltimore city, State of Maryland, have in- 5 vented certainnew and useful Improvements 5 in Compositions for Cleaning LithographicStones, of which the o owing 1s a specificatlon.

My composition consists of the following ingredients combined in theproportions stated, viz: saturated solution of alum or acetic ggig,thirteen ounces; saturate so ut1on o strontian nitrae, seif'ien andone-half ounces; nitric ac1 a out ve ounces; water substantially pure,fifteen ounces. ese

ingredients are thoroughly mingled by agitation.

By the use of the above composition in treating lithogra hic stoneswhich have been reviously used t e former drawings or transers areeasily removed and a new sensitive surface obtained without the usualcustom of grinding, planing, or cutting away the stone by treating thestone with my composition, 2 5 which treatment consists of merelywashing the surface of the stone with a suitable sponge or clothsaturated with the composition. All traces of former usage are removed,and a new and more sensitive surface is produced 0 than by the methodsnow in use, and a great saving of time and labor is effected, and thestone is again prepared for use without the enormous waste of the stoneas caused by the grinding or planing rocess.

Having describe my invention, what I 1 claim, and desire to secure byLetters Patent of the United States, is-

1. The herein described composition of matter, consisting of an acidreacting c01n pound, a solution of strontian nitrate, nitric acid andwater substantially as described and for the pur ose specified.

2. The erein-described composition of matter for preparing lithographicstones after having been previously used, consisting of a solution ofacetic acid, thirteen ounces, a solution of strontian nitrate, seven anda half ounces, nitric acid, about five ounces, and water substantiallypure, fifteen ounces, substantially as described.

3. The herein-described composition of matter for preparing lithographicstones after having been previously used, consisting of a solution of anacid reacting compound, thirteen ounces; a solution of strontiannitrate, seven and a half ounces, nitric acid, about five ounces, andwater substantially pure fifteen ounces, substantiall as described.

In testimony whereof l aflix my signature in presence of two witnesses.

JOSEPH JAMES.

Witnesses:

E. WALTON BREWINGTON, MARY M. MAGRAW.

